Understanding Variations of Soil Mapping Units and Associated Data for Forensic Science

Soil samples have potential to be useful in forensic investigations, but their utility may be limited due to the inherent variability of soil properties, the wide array of analytical methods, and complexity of data analysis. This study examined the differentiation of similar soils based on both gross (texture, color, mineralogy) and explicit soil properties (elemental composition, cation exchange, Fe‐oxyhydroxides). Soils were collected from Fallbrook and adjacent map units from Riverside and San Diego Counties in California. Samples were characterized using multiple techniques, including chemical extracts, X‐ray diffraction (XRD), and Fourier transform infrared spectroscopy. Results were analyzed using multiple analytical approaches to compare counties and land uses. Some analyses (XRD, extractions) were better at distinguishing among samples than others (color, texture). Ratios of rare earth elements were particularly useful for distinguishing samples between counties. This potential to “fingerprint” soils illustrates the usefulness of a comprehensive soil database for criminal investigators.     

The transfer and persistence of trace particulates: experimental studies using clothing fabrics.

A series of experiments were conducted using various types of pollen grain, powder and metal particulates to determine their persistence on a range of different types of materials. The decay curves generated in the repeated experiments all broadly conform to those obtained and already presented in the literature for fibres and glass particulates. The experiments presented in this paper were conducted for up to 647 hours for individual runs and it was found that a general rule existed that it was the material type rather than the particulate type that was the major controlling factor in the persistence of particles. For the pollen grain experiments the overall theory is sustained; there is a significant loss initially followed by a slower decay although this is not precise given the varied nature of palynomorph types. The manner by which the particulates were introduced onto the material had an initial immediate effect, however, the persistence of these particulates over longer periods of time was generally unaffected.     

The forensic analysis of soils and sediment taken from the cast of a footprint

The routine production of a cast of a shoe-print taken in soil provides information other than shoe size and gait. Material adhering to the surface of the cast represents the preservation of the moment of footprint impression. The analysis of the interface between the cast and soil is therefore a potentially lucrative source of information for forensic reconstruction. These principles are demonstrated with reference to a murder case which took place in the English Midlands. The cast of a footprint provided evidence of a two-way transfer of material between the sole of a boot and the soil of a recently ploughed field. Lumps of soil, which had dried on a boot, were deposited on the field as the footprints were made. Pollen analysis of these lumps of soil indicated that the perpetrator of the imprint had been standing recently in a nearby stream. Fibre analysis together with physical and chemical characteristics of the soil suggested a provenance for contamination of this mud prior to deposition of the footprint. Carbon/nitrogen ratios of the water taken from the cast showed that distilled water had been used thus excluding the possibility of contamination of the boot-soil interface. It was possible to reconstruct three phases of previous activity of the wearer of the boot prior to leaving the footprint in the field after the murder had taken place. This analysis shows the power of integrating different independent techniques in the analysis of hitherto unrecognised forensic materials.     

Fatal bromethalin poisoning

Bromethalin is a neurotoxin found in some rodenticides. A delusional 21-year-old male presented to a hospital with altered mental status the day after ingesting a bromethalin-based rodenticide. He died 7 days after his self-reported exposure to c. 17 mg bromethalin (equivalent to 0.33 mg bromethalin/kg). His clinicopathologic course was characterized by altered mental status, obtundation, increased cerebrospinal fluid pressure, cerebral edema, death, and diffuse histologic vacuolization of the white matter in the central nervous system seen on microscopic examination at autopsy. The presence of a demethylated form of bromethalin in the patient's liver and brain was confirmed by gas chromatography with mass spectrometry. Clinical signs and lesions observed in this patient are similar to those seen in animals poisoned with bromethalin. This case illustrates the potential for bromethalin ingestion to result in fatal human poisoning.     

He sends rain upon the wicked: a panel study of the influence of religiosity on violent victimization

This research investigates low religiosity as a predictor of violent victimization. The theoretical framework the authors present here posits that religiosity should help structure daily activities in such a way as to (a) limit exposure to offenders by encouraging contact with peers who are less deviant, (b) lessen one's target suitability by inhibiting grievance-causing delinquent activity, and (c) enhance guardianship by fostering stronger bonds with parents and school. Thus, although researchers expect religion to be a bivariate predictor of violent victimization, its influence should be indirect. The authors investigate these claims using two waves from the public-use version of the National Longitudinal Study of Adolescent Health (Add Health). The results indicate that religiosity is a correlate of violent victimization. Consistent with these theoretical claims, the effect of religiosity is not direct, but instead occurs indirectly primarily through its influence on self-reported delinquency and peer deviance.     

Remembering and Voting: Theory and Evidence from Amnesic Patients

One of the most prominent claims to emerge from the field of public opinion is that citizens can vote for candidates whose issue positions best reflect their own beliefs even when they cannot remember previously learned stances associated with the candidates. The current experiment provides a unique and powerful examination of this claim by determining whether individuals with profound amnesia, whose severe memory impairments prevent them from remembering specific issue information associated with any particular candidate, can vote for candidates whose issue positions come closest to their own political views. We report here that amnesic patients, despite not being able to remember any issue information, consistently voted for candidates with favored political positions. Thus, sound voting decisions do not require recall or recognition of previously learned associations between candidates and their issue positions. This result supports a multiple memory systems model of political decision making.